JP5239885B2 - Optical waveguide inspection method, optical connector, and optical apparatus - Google Patents

Description

The present invention relates to an optical waveguide inspection method and an optical connector.

Conventionally, the technique described in Patent Document 1 is known in the field related to an optical waveguide inspection method. In the temperature detection device for an optical connector described in Patent Document 1, an optical connector including an optical fiber as an optical waveguide is connected to a receptacle, and temperature detection means is provided on the outer wall surface of the receptacle. The temperature of the receptacle is detected by temperature detecting means provided on the outer wall surface of the receptacle, and the detected temperature of the receptacle is used as the temperature of the optical connector.

JP 2003-107282 A

In the temperature detection apparatus for an optical connector described in Patent Document 1, the temperature of the optical connector is determined by the temperature of the outer wall surface of the receptacle that covers the entire circumference of the optical connector. For this reason, it is difficult to detect a temperature change of the optical fiber included in the optical connector. Accordingly, an object of the present invention is to provide an optical waveguide inspection method, an optical connector, and an optical device capable of detecting a temperature change of the optical waveguide provided in the optical connector.

The method for inspecting an optical waveguide of the present invention is a method for inspecting the temperature of an optical waveguide provided in an optical connector, the step of injecting measurement light into the optical waveguide, Receiving the reflected light from the diffraction grating provided at the end of the light output side of the waveguide, measuring the wavelength of the reflected light after receiving the reflected light, measuring the wavelength, and then measuring the wavelength And a step of detecting a temperature change at the end of the optical waveguide on the light output side based on the measured value. In the optical waveguide inspection method of the present invention, the wavelength is measured by receiving the reflected light from the diffraction grating provided at the end of the optical waveguide on the light output side. The measured value of the wavelength of the reflected light changes with a temperature change at the end of the optical waveguide on the light output side. For this reason, by measuring the wavelength of the reflected light, it is possible to detect a temperature change at the end of the optical waveguide on the light output side.

Further, the optical waveguide inspection method of the present invention is a method for inspecting the temperature of the optical waveguide provided in the optical connector, the step of injecting the measurement light into the optical waveguide, and after the measurement light is incident on the optical waveguide The first reflected light from the first diffraction grating provided at the light input side end of the optical waveguide and the grating provided at the light output side end of the optical connector and different from the first diffraction grating Receiving the second reflected light from the second diffraction grating with the interval, receiving the first reflected light and the second reflected light, and then receiving the wavelength of the first reflected light and the second reflected light. Measuring each of the wavelengths of the light, measuring the wavelength of the first reflected light and the wavelength of the second reflected light, then measuring the wavelength of the first reflected light and measuring the wavelength of the second reflected light And a step of detecting a temperature change of the optical waveguide based on the value. In the optical waveguide inspection method of the present invention, the first reflected light and the second reflected light are received and the wavelength is measured. The measured value of the wavelength of the first reflected light changes with a temperature change at the end of the optical waveguide on the light input side. Further, the measured value of the wavelength of the second reflected light changes with a temperature change at the end of the optical waveguide on the light output side. For this reason, by measuring the wavelength of the first reflected light and the wavelength of the second reflected light, the temperature change of the end portion on the light output side of the optical waveguide, the temperature change of the end portion on the light input side, Can be detected.

Further, the optical waveguide inspection method of the present invention is a method for inspecting the temperature of the optical waveguide provided in the optical connector, the step of injecting the measurement light into the optical waveguide, and after the measurement light is incident on the optical waveguide The step of receiving reflected light from the diffraction grating provided at the light output side end of the optical waveguide, the step of measuring the intensity of the reflected light after receiving the reflected light, And a step of detecting a temperature change at an end portion on the light output side of the optical waveguide based on the measured value of the intensity. In the optical waveguide inspection method of the present invention, the intensity of reflected light from the diffraction grating is measured. The measured value of the intensity of the reflected light changes with a temperature change at the end of the optical waveguide on the light output side. Therefore, by measuring the intensity of the reflected light, it is possible to detect a temperature change at the end of the optical waveguide on the light output side.

In the optical waveguide inspection method of the present invention, the step of entering the measurement light includes the step of entering the measurement light into the optical waveguide through an optical filter that transmits light of a predetermined wavelength and receiving the reflected light. After the measurement light is incident on the optical waveguide, the step of receiving the reflected light from the diffraction grating provided at the light output side end of the optical waveguide through the optical filter and measuring the intensity of the reflected light is reflected It is preferable to measure the intensity of the reflected light after receiving the light through the optical filter. In this case, the reflected light from the diffraction grating is received through an optical filter, and the intensity is measured. The measured value of the intensity of the reflected light changes with a temperature change at the end of the optical waveguide on the light output side. Therefore, by measuring the intensity of the reflected light, it is possible to detect a temperature change at the end of the optical waveguide on the light output side.

Further, the optical waveguide inspection method of the present invention is a method for inspecting the temperature of the optical waveguide provided in the optical connector, the step of injecting the measurement light into the optical waveguide, and after the measurement light is incident on the optical waveguide Receiving the reflected light from the chirped diffraction grating provided at least on the light output side end of the optical waveguide, measuring the spectrum of the reflected light after receiving the reflected light, and measuring the spectrum And a step of detecting a temperature change of the optical waveguide based on the shape of the spectrum. In the temperature management method for the optical connector of the present invention, the reflected light from the chirped diffraction grating is received and the spectrum of the reflected light is measured. The shape of this spectrum changes as the temperature inside the optical waveguide changes. For this reason, the temperature change inside the optical waveguide can be detected by measuring the spectrum of the reflected light.

The optical device of the present invention includes an optical connector having a plurality of optical waveguides including an optical waveguide provided with a first diffraction grating at an end portion on the light output side, a driving circuit, and a laser beam in the optical waveguide. An incident laser light source and a temperature change detection unit are provided, and the temperature change detection unit includes a measurement light source for entering measurement light into an optical waveguide provided with the first diffraction grating, and reflection from the first diffraction grating. Receiving light, measuring the wavelength or intensity, detecting the temperature change at the optical output end of the optical waveguide based on the measured value of the wavelength or intensity, and from the laser light source based on the detection result of the temperature change A light receiving unit that transmits a signal for controlling the intensity of the emitted laser light to the drive circuit . In the optical connector of the optical device of the present invention, the plurality of optical waveguides include an optical waveguide having a first diffraction grating provided at an end portion on the light output side and reflecting light of a predetermined wavelength. For this reason, when the measurement light enters the optical waveguide provided with the first diffraction grating, a part of the measurement light is reflected by the first diffraction grating. The value of the wavelength of the reflected light that is reflected changes with a temperature change at the end of the optical waveguide on the light output side. For this reason, it is possible to detect a temperature change at the end of the optical waveguide on the light output side by receiving the reflected light and measuring the wavelength.

The optical connector of the present invention is an optical connector provided with a plurality of optical waveguides, and the plurality of optical waveguides includes an optical waveguide having a first diffraction grating at an end portion on the light output side . The optical waveguide having the diffraction grating further includes a second diffraction grating provided at an end portion on the light input side, and the grating interval of the second diffraction grating is different from the grating interval of the first diffraction grating. It is characterized by . In this case, the optical waveguide provided with the first diffraction grating further includes a second diffraction grating provided at the end on the light input side. For this reason, when the measurement light is incident, a part is reflected by the first diffraction grating and a part is reflected by the second diffraction grating. The wavelength of the reflected light from the first diffraction grating changes with a temperature change at the end of the optical waveguide on the light output side. Further, the wavelength of the reflected light from the second diffraction grating changes with a temperature change at the end of the optical waveguide on the light input side. Therefore, by measuring the wavelength by receiving the reflected light from the first diffraction grating and the second diffraction grating, the temperature change at the end portion on the light output side of the optical waveguide and the temperature on the light input side of the optical waveguide Change can be detected.

The optical connector of the present invention is an optical connector provided with a plurality of optical waveguides, and the plurality of optical waveguides includes an optical waveguide having a first diffraction grating at an end portion on the light output side . optical waveguide having a grating further comprises an optical filter which transmits light of a predetermined wavelength which is provided at an end portion of the light input side, characterized in that. In this case, the optical waveguide provided with the first diffraction grating includes an optical filter that transmits light of a predetermined wavelength at the end of the optical waveguide on the light input side. When measurement light is incident on the optical waveguide, a part of the measurement light passes through the optical filter and is reflected by the first diffraction grating. The reflected light is transmitted through the optical filter and received. The intensity of the received reflected light varies with a temperature change at the end of the optical waveguide on the light output side. Therefore, by measuring the intensity of the reflected light, it is possible to detect a temperature change at the end of the optical waveguide on the light output side.

In addition, the optical device of the present invention includes an optical connector having a plurality of optical waveguides including an optical waveguide provided with a chirped diffraction grating at least at an end on the light output side, and a drive circuit and laser light is incident on the optical waveguide. And a temperature change detection unit, the temperature change detection unit receiving a measurement light source for entering measurement light into an optical waveguide provided with a chirped diffraction grating, and receiving reflected light from the chirped diffraction grating The drive circuit measures the spectrum, detects the temperature change of the optical waveguide based on the shape of the spectrum, and controls the intensity of the laser light emitted from the laser light source based on the detection result of the temperature change And a light receiving unit that transmits the light . In the optical connector of the optical device of the present invention, the plurality of optical waveguides include an optical waveguide provided with a chirped diffraction grating. For this reason, when measurement light is incident on this optical waveguide, a part is reflected by the chirped diffraction grating. The shape of the spectrum of the reflected light reflected by the chirped diffraction grating changes as the temperature inside the optical waveguide changes. For this reason, the temperature change inside the optical waveguide can be detected by measuring the spectrum of the reflected light.

ADVANTAGE OF THE INVENTION According to this invention, the inspection method of an optical waveguide, an optical connector, and an optical apparatus which can detect the temperature change of the optical waveguide provided in the optical connector can be provided.

It is the figure which represented typically the apparatus structure which concerns on embodiment. It is the figure which represented typically the apparatus structure which concerns on embodiment. It is a figure for demonstrating the inspection method of the optical waveguide which concerns on 1st Embodiment and 2nd Embodiment. It is a figure for demonstrating the inspection method of the optical waveguide which concerns on 3rd Embodiment and 4th Embodiment. It is the figure which represented typically the apparatus structure which concerns on embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, if possible, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(First Embodiment) FIG. 1A is a diagram schematically showing an apparatus configuration according to the first embodiment. As shown in FIG. 1A, the optical connector 1 and the optical connector 2 are connectors for connecting an optical fiber 3 for transmitting laser light to another optical fiber 4. The optical connector 1 has an optical waveguide 5. The optical waveguide 5 includes a waveguide type diffraction grating 9. The waveguide type diffraction grating 9 is provided at the end 7 on the light output side of the optical waveguide 5. The optical connector 2 has an optical waveguide 8. The optical input end 6 of the optical waveguide 5 is optically connected to the optical fiber 3, and the optical output end 7 of the optical waveguide 5 is connected to the optical input end of the optical waveguide 8. . The end of the optical waveguide 8 on the light output side is optically connected to the optical fiber 4. One end of the optical fiber 3 is optically connected to the end 6 on the light input side of the optical waveguide 5, and the other end is optically connected to the laser light source 10 and the temperature change detection unit 11 via the optical system 16. ing.

FIG. 2 is a diagram illustrating a specific configuration example of the laser light source 10, the temperature change detection unit 11, and the optical system 16. The laser light source 10 includes, for example, a laser diode (not shown) and a laser diode drive circuit (not shown). The laser light source 10 makes a laser beam incident on the optical fiber 3 through the optical system 16. The temperature change detection unit 11 includes a measurement light source 14 and a light receiving unit 15. The measurement light source 14 is, for example, a white light source. The measurement light source 14 causes measurement light to enter the optical fiber via the optical system 16. The light receiving unit 15 is connected to the laser light source 10 and includes, for example, a light receiving element such as a photodiode (not shown), an A / D converter, a CPU, a ROM, a RAM, and the like. The light receiving unit 15 receives the reflected light transmitted through the optical fiber 3 through the optical system 16 and converts it into an electrical signal, and measures and analyzes the wavelength, intensity, and the like of the received light. Further, the light receiving unit 15 transmits a signal for controlling the intensity of the laser light emitted from the laser light source 10 to the drive circuit of the laser light source 10 based on the analysis result such as the wavelength and intensity of the reflected light. .

The optical system 16 includes lenses 12, 13, 17, 19 and half mirrors 18, 20. Laser light emitted from the laser light source 10 enters the optical fiber 3 through the lens 12, the half mirror 18, and the lens 13. The measurement light emitted from the measurement light source 14 reaches the half mirror 18 through the lens 17 and the half mirror 20, is reflected by the half mirror 18, and then enters the optical fiber 3 through the lens 13. The reflected light transmitted through the optical fiber 3 reaches the half mirror 18 through the lens 13, is reflected by the half mirror 18, and reaches the half mirror 20. Further, the light is reflected by the half mirror 20 and then enters the light receiving unit 15 through the lens 19.

Next, the optical connector inspection method according to the first embodiment will be described with reference to FIGS. 1 (a), 2 and 3 (a). FIG. 3A illustrates the relationship between the wavelength of the reflected light and the light intensity, the horizontal axis represents the wavelength, and the vertical axis represents the reflected light intensity. First, the measurement light source 14 of the temperature change detection unit 11 makes measurement light incident on the optical waveguide 5. Subsequently, the light receiving unit 15 of the temperature change detecting unit 11 receives the reflected light from the waveguide type diffraction grating 9 provided at the end 7 on the light output side of the optical waveguide 5. Subsequently, the light receiving unit 15 measures the wavelength of the reflected light, and detects the temperature change of the end 7 on the light output side of the optical waveguide 5 based on the measured value. Specifically, as shown in FIG. 3A, the wavelength measurement value λ ₁ changes with the temperature change of the end portion 7 on the light output side of the optical waveguide 5. By detecting the change in the measured value λ ₁ of this wavelength, the temperature change at the end 7 on the light output side of the optical waveguide 5 is detected. Subsequently, when the detected temperature change is greater than or equal to a predetermined value (when the wavelength of the received reflected light has changed more than a predetermined value), the light receiving unit 15 assumes that this temperature change is caused by laser light irradiation. A signal for controlling the intensity of the laser beam emitted from the laser beam is transmitted to the drive circuit of the laser light source 10.

As described above, in the first embodiment, the light receiving unit 15 receives the reflected light from the waveguide type diffraction grating 9 provided at the end 7 on the light output side of the optical waveguide 5 and measures the wavelength. To do. The wavelength of the reflected light changes with the temperature change of the end 7 on the light output side of the optical waveguide 5. Therefore, the light receiving unit 15 can detect the temperature change of the end 7 on the light output side of the optical waveguide 5 by measuring the wavelength of the reflected light. Furthermore, since the light receiving unit 15 can control the intensity of the laser light emitted from the laser light source 10 in accordance with the detected temperature change, the end 7 on the light output side of the optical waveguide 5 caused by the laser light. Temperature change can be suppressed.

(Second Embodiment) FIG. 1 (b) is a diagram schematically showing a device configuration according to a second embodiment. As shown in FIG. 1B, the optical connector 1a includes an optical waveguide 5a instead of the optical waveguide 5 of the optical connector 1 of the first embodiment. The optical waveguide 5 a includes a waveguide type diffraction grating 9 and a waveguide type diffraction grating 21. The waveguide type diffraction grating 9 is provided at the end portion 7 on the light output side of the optical waveguide 5a, and the waveguide type diffraction grating 21 is provided at the end portion 6 on the light input side of the optical waveguide 5a. The grating interval of the waveguide type diffraction grating 21 is different from the grating interval of the waveguide type diffraction grating 9. Other configurations of the optical waveguide 5a are the same as those of the optical waveguide 5 of the first embodiment.

Next, an optical connector inspection method according to the second embodiment will be described with reference to FIGS. 1B, 2 and 3B. FIG. 3B illustrates the relationship between the wavelength of the reflected light and the light intensity, the horizontal axis represents the wavelength, and the vertical axis represents the reflected light intensity. First, the measurement light source 14 of the temperature change detection unit 11 enters measurement light into the optical waveguide 5a. Subsequently, the reflected light from the waveguide type diffraction grating 9 provided at the light output side end 7 of the optical waveguide 5a and the waveguide type diffraction grating provided at the light input side end 6 of the optical waveguide 5a. The light receiving unit 15 of the temperature change detecting unit 11 receives the reflected light from the light 21. Subsequently, the light receiving unit 15 measures the wavelengths of these reflected lights, and detects the temperature change of the optical waveguide 5a based on these measured values. The detection of this temperature change will be specifically described. As shown in FIG. 3B, the measured value λ ₂ of the wavelength of the reflected light from the waveguide type diffraction grating 9 changes with the temperature change of the end 7 on the light output side of the optical waveguide 5a. Further, the measured value λ ₃ of the wavelength of the reflected light from the waveguide type diffraction grating 21 changes with the temperature change of the end 6 on the light input side of the optical waveguide 5a. The light receiving unit 15 detects a change in the wavelength measurement value λ ₂ to detect a temperature change in the end 7 on the light output side of the optical waveguide 5, and detects a change in the wavelength measurement value λ _3. The temperature change at the end 6 on the light input side of the optical waveguide 5a is detected. Subsequently, when no temperature change is detected at the end 6 on the light input side and a temperature change of a predetermined level or more is detected at the end 7 on the light output side (the wavelength of the reflected light from the waveguide type diffraction grating 21 is This change in temperature is caused by the irradiation of the laser light emitted from the laser light source 10 only when the wavelength of the reflected light from the waveguide type diffraction grating 9 does not change and the wavelength of the reflected light from the waveguide type diffraction grating 9 changes by a predetermined value or more. As a result, a signal for controlling the intensity of the laser light emitted from the laser light source 10 is transmitted to the drive circuit of the laser light source 10.

As described above, in the second embodiment, the light receiving unit 15 includes the reflected light from the waveguide type diffraction grating 9 provided at the end 7 on the light output side of the optical waveguide 5a and the optical input of the optical waveguide 5a. The reflected light from the waveguide type diffraction grating 21 provided at the end 6 on the side is received and the wavelength is measured. The wavelength of the reflected light from the waveguide type diffraction grating 9 changes as the temperature of the end 7 on the light output side of the optical waveguide 5a changes. Further, the wavelength of the reflected light from the waveguide type diffraction grating 21 changes with the temperature change of the end 6 on the light input side of the optical waveguide 5a. Therefore, by measuring the wavelength of the reflected light from the waveguide type diffraction grating 9 and the wavelength of the reflected light from the waveguide type diffraction grating 21, the temperature change at the end 6 on the light input side of the optical waveguide 5a The temperature change of the end 7 on the light output side can be detected. Further, the light receiving unit 15 controls the intensity of the laser light emitted from the laser light source 10 according to the detected temperature change only when the temperature change is detected only at the end 7 on the light output side of the optical waveguide 5a. Therefore, the temperature change of the end 7 on the light output side of the optical waveguide 5a caused by the laser light can be efficiently suppressed.

(Third Embodiment) FIG. 1 (c) is a diagram schematically showing an apparatus configuration according to a third embodiment. As shown in FIG. 1C, the optical connector 1b includes an optical waveguide 5b instead of the optical waveguide 5 of the optical connector 1 of the first embodiment. The optical waveguide 5b includes a waveguide type diffraction grating 9 and a band transmission filter 22 as an optical filter. The waveguide type diffraction grating 9 is provided at the end 7 on the light output side of the optical waveguide 5b, and the band pass filter 22 is provided at the end 6 on the light input side of the optical waveguide 5b. The band transmission filter 22 transmits light in a predetermined wavelength band. Other configurations of the optical waveguide 5c are the same as those of the optical waveguide 5 of the first embodiment.

Next, an optical connector inspection method according to the third embodiment will be described with reference to FIGS. 1C, 2 and 4A. FIG. 4A illustrates the relationship between the intensity of reflected light and the temperature at the end on the light output side, the horizontal axis represents temperature, and the vertical axis represents reflected light intensity. First, the measurement light source 14 of the temperature change detection unit 11 enters measurement light into the optical waveguide 5b. This measurement light passes through the band-pass filter 22 provided at the end 6 on the light input side of the optical waveguide 5b, and is guided by the waveguide type diffraction grating 9 provided at the end 7 on the light output side of the optical waveguide 5b. Reflected. The light receiving unit 15 of the temperature change detecting unit 11 receives the reflected light from the waveguide type diffraction grating 9. Subsequently, the light receiving unit 15 measures the intensity of the received reflected light, and detects the temperature change of the end 7 on the light output side of the optical waveguide 5b based on the measured value. The detection of this temperature change will be specifically described. When a temperature change occurs at the end 7 on the light output side where the waveguide type diffraction grating 9 is provided, the wavelength of the reflected light from the waveguide type diffraction grating 9 changes. When the wavelength of the reflected light from the waveguide type diffraction grating 9 changes and a deviation from the transmission wavelength region of the band pass filter 22 occurs, the intensity of the reflected light that passes through the band pass filter 22 changes. Thus, when the temperature change occurs at the end 7 on the light output side, the intensity of the reflected light from the waveguide type diffraction grating 9 that is transmitted through the band-pass filter 22 and received by the light receiving unit 15 changes. Therefore, the light receiving unit 15 can detect the temperature change of the end 7 on the light output side based on the change in the intensity of the reflected light. Subsequently, when the detected temperature change is greater than or equal to a predetermined value (when the intensity of the received reflected light has changed more than a predetermined value), the light receiving unit 15 determines that the temperature change is caused by laser light irradiation. A signal for controlling the intensity of the laser light emitted from 10 is transmitted to the drive circuit of the laser light source 10.

As described above, in the third embodiment, the light receiving unit 15 is light reflected by the waveguide type diffraction grating 9 provided at the end 7 on the light output side of the optical waveguide 5b and transmitted through the band pass filter 22. Receive (reflected light) and measure the intensity. The intensity of the reflected light changes with the temperature change of the end 7 on the light output side of the optical waveguide 5b. Therefore, the light receiving unit 15 can detect a temperature change of the end 7 on the light output side of the optical waveguide 5b by measuring the intensity of the reflected light. Furthermore, since the light receiving unit 15 can control the intensity of the laser light emitted from the laser light source 10 in accordance with the detected temperature change, the end 7 on the light output side of the optical waveguide 5b caused by the laser light. Temperature change can be suppressed. In the third embodiment, the band-pass filter 22 is provided at the end 6 on the light input side of the optical waveguide 5b. However, the present invention is not limited to this. For example, as shown in FIG. 2, the band-pass filter 23 can be provided between the measurement light source 14 and the optical waveguide 5. According to this configuration, the measurement light is incident on the optical waveguide 5 b through the band transmission filter 23. Furthermore, instead of the band pass filters 22 and 23, an edge filter that transmits light on the short wavelength side or light on the long wavelength side can be used. Further, instead of using the band-pass filters 22 and 23, a laser light source having a fixed emission wavelength may be used as the measurement light source 14. In this case, the measurement light source 14 of the temperature change detection unit 11 enters the measurement light with the emission wavelength fixed to the optical waveguide 5. Subsequently, the light receiving unit 15 of the temperature change detecting unit 11 receives the reflected light from the waveguide type diffraction grating 9 provided at the end 7 on the light output side of the optical waveguide 5. Subsequently, the light receiving unit 15 measures the intensity of the reflected light, and detects a temperature change of the end 7 on the light output side of the optical waveguide 5 based on the measured value. Specifically, as shown in FIG. 4A, the measured intensity value changes with the temperature change of the end portion 7 on the light output side of the optical waveguide 5, so that the light receiving unit 15 has this intensity. By detecting the change in the measured value, the temperature change at the end 7 on the light output side of the optical waveguide 5 is detected. Subsequently, when the detected temperature change is greater than or equal to a predetermined value (when the intensity of the received reflected light has changed more than a predetermined value), the light receiving unit 15 assumes that this temperature change is caused by laser light irradiation. A signal for controlling the intensity of the laser beam emitted from the laser beam is transmitted to the drive circuit of the laser light source 10.

(Fourth Embodiment) FIG. 1 (d) is a diagram schematically showing a device configuration according to a fourth embodiment. As shown in FIG. 1D, the optical connector 1c includes an optical waveguide 5c instead of the optical waveguide 5 of the optical connector 1 of the first embodiment. The optical waveguide 5 c includes a chirped diffraction grating 24. In the chirped diffraction grating 24, the grating interval changes from the end 6 on the light input side of the optical waveguide 5c toward the end 7 on the light output side. For this reason, the chirped diffraction grating 24 reflects light having different wavelengths depending on the position in the optical waveguide 5c. The chirped diffraction grating 24 has at least a region provided at the end 7 on the light output side of the optical waveguide 5c. The chirped diffraction grating 24 may have a region provided at the end 6 on the light input side of 5c. Other configurations of the optical waveguide 5c are the same as those of the optical waveguide 5 of the first embodiment.

Next, an optical connector inspection method according to the fourth embodiment will be described with reference to FIGS. 1D, 2 and 4B. FIG. 4B illustrates the relationship (spectrum) between the wavelength of reflected light and the light intensity, where the horizontal axis represents the wavelength and the vertical axis represents the reflected light intensity. The end D1 on the long wavelength side of the spectrum shown in FIG. 4B represents the intensity of the reflected light from the end 7 on the light output side of the optical waveguide 5c, and the end D2 on the short wavelength side indicates the optical waveguide 5c. Represents the intensity of the reflected light from the end 6 on the light input side. First, the measurement light source 14 of the temperature change detection unit 11 enters measurement light into the optical waveguide 5c. Subsequently, the light receiving unit 15 of the temperature change detecting unit 11 receives the reflected light from the chirped diffraction grating 24 provided in the optical waveguide 5c. Subsequently, the light receiving unit 15 measures the spectrum of the received reflected light, and detects the temperature change of the optical waveguide 5c based on the shape of the measured spectrum. The shape of the spectrum shown in FIG. 4B changes with a temperature change inside the optical waveguide 5c. The light receiving unit 15 detects a temperature change in the optical waveguide 5c by detecting a change in the shape of the spectrum. Subsequently, the light receiving unit 15 is used when only the shape of the spectrum at the end D1 is changed by a predetermined value or more, that is, when a temperature change of a predetermined value or more is detected only at the end 7 on the light output side of the optical waveguide 5c. As long as this temperature change is caused by the irradiation of the laser light emitted from the laser light source 10, a signal for controlling the intensity of the laser light emitted from the laser light source 10 is transmitted to the drive circuit of the laser light source 10. To do.

As described above, in the fourth embodiment, the light receiving unit 15 receives the reflected light from the chirped diffraction grating 24 provided in the optical waveguide 5c and measures the spectrum. The shape of this spectrum changes as the temperature inside the optical waveguide 5c changes. For this reason, the temperature change inside the optical waveguide 5c can be detected by measuring the spectrum of the reflected light. Further, the light receiving unit 15 controls the intensity of the laser light emitted from the laser light source 10 only when a temperature change is detected only at the end 7 on the light output side of the optical waveguide 5c. Therefore, the temperature change of the end 7 on the light output side of the optical waveguide 5a caused by the laser light can be efficiently suppressed.

(Fifth Embodiment) FIG. 5A is a diagram schematically showing the configuration of an optical connector 25 according to a fifth embodiment. As shown in FIG. 5A, the optical connector 25 and the optical connector 33 are connectors for optically connecting the plurality of optical fibers 28 to the other plurality of optical fibers 34. The optical connector 25 includes a plurality of optical waveguides 26. The plurality of optical waveguides 26 include at least one optical waveguide 5 similar to that of the first embodiment. The optical connector 33 includes a plurality of optical waveguides 32. The number of the plurality of optical fibers 28, the number of the plurality of optical waveguides 26, the number of the plurality of optical waveguides 32, and the number of the plurality of optical fibers 34 are the same. The light input side ends of the plurality of optical waveguides 26 are optically connected to the plurality of optical fibers 28, and the light output side ends of the plurality of optical waveguides 26 are on the light input side of the plurality of optical waveguides 32. Optically connected to the end. The ends on the light output side of the plurality of optical waveguides 32 are optically connected to the plurality of optical fibers 34. Each of the plurality of optical fibers 28 is optically connected to one end of each of the plurality of optical waveguides 26 on the light input side at one end, and is connected to the laser light source 10 and the temperature via the optical system 16 at the other end. Optically connected to the change detector 11.

As described above, the optical connector 25 according to the fifth embodiment includes the same optical waveguide 5 as that of the first embodiment. Therefore, by receiving the reflected light from the waveguide type diffraction grating 9 of the optical waveguide 5 and measuring the wavelength, the temperature change of the end portion 7 on the light output side of the optical waveguide 5 (and the plurality of optical waveguides 26). Temperature change at the end on the light output side). The plurality of optical waveguides 26 may include two or more optical waveguides 5.

(Sixth Embodiment) FIG. 5B is a diagram schematically showing the configuration of the apparatus according to the sixth embodiment. As shown in FIG. 5B, the optical connector 25a includes a plurality of optical waveguides 26a instead of the plurality of optical waveguides 26 of the optical connector 25 of the fifth embodiment. The plurality of optical waveguides 26a include at least one optical waveguide 5a similar to that of the second embodiment. Other configurations of the optical connector 25a are the same as those of the optical connector 25 of the fifth embodiment. Thus, the optical connector 25a according to the sixth embodiment includes the same optical waveguide 5a as that of the second embodiment. Therefore, by receiving the reflected light from the waveguide type diffraction grating 9 and the waveguide type diffraction grating 21 and measuring the wavelength, the temperature change of the end portion 7 on the light output side of the optical waveguide 5a (and a plurality of more) Temperature change at the light output side end of the optical waveguide 26a) and temperature change at the light input side end 6 of the optical waveguide 5a (further, temperature changes at the light input side ends of the plurality of optical waveguides 26a). And can be detected. The plurality of optical waveguides 26a may include two or more optical waveguides 5a.

(Seventh Embodiment) FIG. 5 (c) is a diagram schematically showing a device configuration according to a seventh embodiment. As shown in FIG. 5C, the optical connector 25b includes a plurality of optical waveguides 26b instead of the plurality of optical waveguides 26 of the optical connector 25 of the fifth embodiment. The plurality of optical waveguides 26b include at least one optical waveguide 5b similar to that of the third embodiment. Other configurations of the optical connector 25b are the same as those of the optical connector 25 of the fifth embodiment. Thus, the optical connector 25b according to the seventh embodiment includes the same optical waveguide 5b as that of the third embodiment. Therefore, by receiving the light (reflected light) reflected by the waveguide type diffraction grating 9 and transmitted through the band-pass filter 22, and measuring the intensity, the temperature change of the end portion 7 on the light output side of the optical waveguide 5b. (Further, the temperature change at the light output end of the plurality of waveguides 26b) can be detected. The plurality of waveguides 26b may include two or more optical waveguides 5b. Instead of the band-pass filters 22 and 23, an edge filter that transmits light on the short wavelength side or light on the long wavelength side can be used.

(Eighth Embodiment) FIG. 5 (d) is a diagram schematically showing a device configuration according to the eighth embodiment. The optical connector 25c includes a plurality of optical waveguides 26c instead of the plurality of optical waveguides 26 of the optical connector 25 of the fifth embodiment. The plurality of optical waveguides 26c include at least one optical waveguide 5c similar to that of the fourth embodiment. Other configurations of the optical connector 25c are the same as those of the optical connector 25 of the fifth embodiment. Thus, the optical connector 25c according to the eighth embodiment includes the same optical waveguide 5c as that of the fourth embodiment. Therefore, the temperature change in the optical waveguide 5c can be detected by measuring the spectrum of the reflected light from the chirped grating 24. The plurality of optical waveguides 26c may include two or more optical waveguides 5c.

1, 1a, 1b, 1c, 2, 25, 25a, 25b, 25c, 33 ... optical connector, 3, 4 ... optical fiber, 5, 5a, 5b, 5c, 8 ... optical waveguide, 6 ... end on the optical input side , 7 ... Optical output side end, 9, 21 ... Waveguide type diffraction grating, 10 ... Laser light source, 11 ... Temperature change detection part, 12, 13, 17, 19 ... Lens, 14 ... Measurement light source, 15 ... Light receiving section 16... Optical system 18 and 20 Half mirror 22 and 23 Band transmission filter 24 Chirped diffraction grating 26, 26 a, 26 b, 26 c, 32 Multiple optical waveguides 28, 34. Optical fiber.

Claims (9)

A method for inspecting the temperature of an optical waveguide provided in an optical connector,
Injecting measurement light into the optical waveguide;
Receiving the measurement light incident on the optical waveguide, and then receiving reflected light from a diffraction grating provided at an end portion on the light output side of the optical waveguide;
Measuring the wavelength of the reflected light after receiving the reflected light;
After measuring the wavelength, based on the measured value of the wavelength, detecting a temperature change at the end of the optical output side of the optical waveguide,
An optical waveguide inspection method characterized by the above. A method for inspecting the temperature of an optical waveguide provided in an optical connector,
Injecting measurement light into the optical waveguide;
After the measurement light is incident on the optical waveguide, the first reflected light from the first diffraction grating provided at the end on the light input side of the optical waveguide and the end on the light output side of the optical connector Receiving the second reflected light from the second diffraction grating having a grating interval different from that of the first diffraction grating;
Measuring the wavelength of the first reflected light and the wavelength of the second reflected light after receiving the first reflected light and the second reflected light; and
After measuring the wavelength of the first reflected light and the wavelength of the second reflected light, based on the measured value of the wavelength of the first reflected light and the measured value of the wavelength of the second reflected light, Detecting a temperature change of the optical waveguide,
An optical waveguide inspection method characterized by the above. A method for inspecting the temperature of an optical waveguide provided in an optical connector,
Injecting measurement light into the optical waveguide;
Receiving the measurement light incident on the optical waveguide, and then receiving reflected light from a diffraction grating provided at an end portion on the light output side of the optical waveguide;
Measuring the intensity of the reflected light after receiving the reflected light;
After measuring the intensity, detecting a temperature change at the end of the optical waveguide on the light output side based on the measured value of the intensity, and
An optical waveguide inspection method characterized by the above. The step of making the measurement light incident includes making the measurement light incident on the optical waveguide through an optical filter that transmits light of a predetermined wavelength,
In the step of receiving the reflected light, after the measurement light is incident on the optical waveguide, the reflected light from the diffraction grating provided at the light output end of the optical waveguide is passed through the optical filter. Receive light,
The step of measuring the intensity of the reflected light includes measuring the intensity of the reflected light after receiving the reflected light through the optical filter.
The method for inspecting an optical waveguide according to claim 3. A method for inspecting the temperature of an optical waveguide provided in an optical connector,
Injecting measurement light into the optical waveguide;
Receiving the reflected light from the chirped diffraction grating provided at least on the light output side end of the optical waveguide after the measurement light is incident on the optical waveguide;
Measuring the spectrum of the reflected light after receiving the reflected light;
After measuring the spectrum, detecting a temperature change of the optical waveguide based on the shape of the spectrum,
An optical waveguide inspection method characterized by the above. An optical connector having a plurality of optical waveguides,
Wherein the plurality of optical waveguides, see contains an optical waveguide having a first diffraction grating to the end of the light output side,
The optical waveguide having the first diffraction grating further includes a second diffraction grating provided at an end on the light input side ,
The grating interval of the second diffraction grating is different from the grating interval of the first diffraction grating ,
An optical connector characterized by that. An optical connector having a plurality of optical waveguides ,
The plurality of optical waveguides include an optical waveguide having a first diffraction grating at an end on the light output side ,
The optical waveguide having the first diffraction grating further includes an optical filter that transmits light of a predetermined wavelength provided at an end portion on the light input side.
An optical connector characterized by that. An optical connector having a plurality of optical waveguides including an optical waveguide provided with a first diffraction grating at an end on the optical output side, a laser light source having a drive circuit and entering laser light into the optical waveguide, and temperature change A detection unit ,
The temperature change detection unit receives a measurement light source that enters measurement light into an optical waveguide provided with the first diffraction grating, and receives reflected light from the first diffraction grating to measure a wavelength or intensity. Detecting the temperature change of the end of the optical waveguide on the light output side based on the measured value of the wavelength or intensity, and the intensity of the laser light emitted from the laser light source based on the detection result of the temperature change A light receiving section that transmits a signal for controlling the drive circuit to the drive circuit,
An optical device . An optical connector having a plurality of optical waveguides including an optical waveguide provided with a chirped diffraction grating at least at an end portion on the light output side, a laser light source having a drive circuit and entering laser light into the optical waveguide, and temperature change detection With
The temperature change detection unit is configured to measure a spectrum by receiving a measurement light source for entering measurement light into an optical waveguide provided with the chirped diffraction grating, and reflected light from the chirped diffraction grating, to obtain a shape of the spectrum. Detecting a temperature change of the optical waveguide based on, and a light receiving unit for transmitting to the drive circuit a signal for controlling the intensity of the laser light emitted from the laser light source based on the detection result of the temperature change; Having
An optical device .

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